303 lines
8.5 KiB
C
303 lines
8.5 KiB
C
|
/*
|
||
|
|
* Asterisk -- An open source telephony toolkit.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2021, Naveen Albert
|
||
|
|
*
|
||
|
|
* Naveen Albert <asterisk@phreaknet.org>
|
||
|
|
*
|
||
|
|
* See http://www.asterisk.org for more information about
|
||
|
|
* the Asterisk project. Please do not directly contact
|
||
|
|
* any of the maintainers of this project for assistance;
|
||
|
|
* the project provides a web site, mailing lists and IRC
|
||
|
|
* channels for your use.
|
||
|
|
*
|
||
|
|
* This program is free software, distributed under the terms of
|
||
|
|
* the GNU General Public License Version 2. See the LICENSE file
|
||
|
|
* at the top of the source tree.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*! \file
|
||
|
|
*
|
||
|
|
* \brief Function that drops specified frames from channels
|
||
|
|
*
|
||
|
|
* \author Naveen Albert <asterisk@phreaknet.org>
|
||
|
|
*
|
||
|
|
* \ingroup functions
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*** MODULEINFO
|
||
|
|
<support_level>extended</support_level>
|
||
|
|
***/
|
||
|
|
|
||
|
|
#include "asterisk.h"
|
||
|
|
|
||
|
|
#include "asterisk/module.h"
|
||
|
|
#include "asterisk/channel.h"
|
||
|
|
#include "asterisk/pbx.h"
|
||
|
|
#include "asterisk/framehook.h"
|
||
|
|
|
||
|
|
/*** DOCUMENTATION
|
||
|
|
<function name="FRAME_DROP" language="en_US">
|
||
|
|
<since>
|
||
|
|
<version>16.21.0</version>
|
||
|
|
<version>18.7.0</version>
|
||
|
|
<version>19.0.0</version>
|
||
|
|
</since>
|
||
|
|
<synopsis>
|
||
|
|
Drops specific frame types in the TX or RX direction on a channel.
|
||
|
|
</synopsis>
|
||
|
|
<syntax>
|
||
|
|
<parameter name="direction" required="true">
|
||
|
|
<para>List of frame types to be dropped for the specified direction. Direction can be <literal>TX</literal> or <literal>RX</literal>. The <literal>TX</literal> direction will prevent Asterisk from sending frames to a channel, and the <literal>RX</literal> direction will prevent Asterisk from receiving frames from a channel.</para>
|
||
|
|
<para>Subsequent calls to this function will replace previous settings, allowing certain frames to be dropped only temporarily, for instance.</para>
|
||
|
|
<para>Below are the different types of frames that can be dropped. Other actions may need to be taken in conjunction with use of this function:
|
||
|
|
for instance, if you drop ANSWER control frames, you should explicitly use <literal>Progress()</literal> for your call or undesired behavior
|
||
|
|
may occur.</para>
|
||
|
|
<enumlist>
|
||
|
|
<enum name = "DTMF_BEGIN" />
|
||
|
|
<enum name = "DTMF_END" />
|
||
|
|
<enum name = "VOICE" />
|
||
|
|
<enum name = "VIDEO" />
|
||
|
|
<enum name = "CONTROL" />
|
||
|
|
<enum name = "NULL" />
|
||
|
|
<enum name = "IAX" />
|
||
|
|
<enum name = "TEXT" />
|
||
|
|
<enum name = "TEXT_DATA" />
|
||
|
|
<enum name = "IMAGE" />
|
||
|
|
<enum name = "HTML" />
|
||
|
|
<enum name = "CNG" />
|
||
|
|
<enum name = "MODEM" />
|
||
|
|
</enumlist>
|
||
|
|
<para>The following CONTROL frames can also be dropped:</para>
|
||
|
|
<enumlist>
|
||
|
|
<enum name = "RING" />
|
||
|
|
<enum name = "RINGING" />
|
||
|
|
<enum name = "ANSWER" />
|
||
|
|
<enum name = "BUSY" />
|
||
|
|
<enum name = "TAKEOFFHOOK" />
|
||
|
|
<enum name = "OFFHOOK" />
|
||
|
|
<enum name = "CONGESTION" />
|
||
|
|
<enum name = "FLASH" />
|
||
|
|
<enum name = "WINK" />
|
||
|
|
<enum name = "PROGRESS" />
|
||
|
|
<enum name = "PROCEEDING" />
|
||
|
|
<enum name = "HOLD" />
|
||
|
|
<enum name = "UNHOLD" />
|
||
|
|
<enum name = "VIDUPDATE" />
|
||
|
|
<enum name = "CONNECTED_LINE" />
|
||
|
|
<enum name = "REDIRECTING" />
|
||
|
|
</enumlist>
|
||
|
|
</parameter>
|
||
|
|
</syntax>
|
||
|
|
<description>
|
||
|
|
<para>Examples:</para>
|
||
|
|
<example title="Drop only DTMF frames towards this channel">
|
||
|
|
exten => 1,1,Set(FRAME_DROP(TX)=DTMF_BEGIN,DTMF_END)
|
||
|
|
</example>
|
||
|
|
<example title="Drop only Answer control frames towards this channel">
|
||
|
|
exten => 1,1,Set(FRAME_DROP(TX)=ANSWER)
|
||
|
|
</example>
|
||
|
|
<example title="Drop only DTMF frames received on this channel">
|
||
|
|
exten => 1,1,Set(FRAME_DROP(RX)=DTMF_BEGIN,DTMF_END)
|
||
|
|
</example>
|
||
|
|
</description>
|
||
|
|
</function>
|
||
|
|
***/
|
||
|
|
|
||
|
|
static struct {
|
||
|
|
enum ast_frame_type type;
|
||
|
|
const char *str;
|
||
|
|
} frametype2str[] = {
|
||
|
|
{ AST_FRAME_DTMF_BEGIN, ",DTMF_BEGIN," },
|
||
|
|
{ AST_FRAME_DTMF_END, ",DTMF_END," },
|
||
|
|
{ AST_FRAME_VOICE, ",VOICE," },
|
||
|
|
{ AST_FRAME_VIDEO, ",VIDEO," },
|
||
|
|
{ AST_FRAME_CONTROL, ",CONTROL," },
|
||
|
|
{ AST_FRAME_NULL, ",NULL," },
|
||
|
|
{ AST_FRAME_IAX, ",IAX," },
|
||
|
|
{ AST_FRAME_TEXT, ",TEXT," },
|
||
|
|
{ AST_FRAME_TEXT_DATA, ",TEXT_DATA," },
|
||
|
|
{ AST_FRAME_IMAGE, ",IMAGE," },
|
||
|
|
{ AST_FRAME_HTML, ",HTML," },
|
||
|
|
{ AST_FRAME_CNG, ",CNG," },
|
||
|
|
{ AST_FRAME_MODEM, ",MODEM," },
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct {
|
||
|
|
int type;
|
||
|
|
const char *str;
|
||
|
|
} controlframetype2str[] = {
|
||
|
|
{ AST_CONTROL_RING, ",RING," },
|
||
|
|
{ AST_CONTROL_RINGING, ",RINGING," },
|
||
|
|
{ AST_CONTROL_ANSWER, ",ANSWER," },
|
||
|
|
{ AST_CONTROL_BUSY, ",BUSY," },
|
||
|
|
{ AST_CONTROL_TAKEOFFHOOK, ",TAKEOFFHOOK," },
|
||
|
|
{ AST_CONTROL_OFFHOOK, ",OFFHOOK," },
|
||
|
|
{ AST_CONTROL_CONGESTION, ",CONGESTION," },
|
||
|
|
{ AST_CONTROL_FLASH, ",FLASH," },
|
||
|
|
{ AST_CONTROL_WINK, ",WINK," },
|
||
|
|
{ AST_CONTROL_PROGRESS, ",PROGRESS," },
|
||
|
|
{ AST_CONTROL_PROCEEDING, ",PROCEEDING," },
|
||
|
|
{ AST_CONTROL_HOLD, ",HOLD," },
|
||
|
|
{ AST_CONTROL_UNHOLD, ",UNHOLD," },
|
||
|
|
{ AST_CONTROL_VIDUPDATE, ",VIDUPDATE," },
|
||
|
|
{ AST_CONTROL_CONNECTED_LINE, ",CONNECTED_LINE," },
|
||
|
|
{ AST_CONTROL_REDIRECTING, ",REDIRECTING," },
|
||
|
|
};
|
||
|
|
|
||
|
|
enum direction {
|
||
|
|
TX = 0,
|
||
|
|
RX,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct frame_drop_data {
|
||
|
|
enum direction list_type;
|
||
|
|
int values[ARRAY_LEN(frametype2str)];
|
||
|
|
int controlvalues[ARRAY_LEN(controlframetype2str)];
|
||
|
|
};
|
||
|
|
|
||
|
|
static void datastore_destroy_cb(void *data) {
|
||
|
|
ast_free(data);
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct ast_datastore_info frame_drop_datastore = {
|
||
|
|
.type = "framedrop",
|
||
|
|
.destroy = datastore_destroy_cb
|
||
|
|
};
|
||
|
|
|
||
|
|
static void hook_destroy_cb(void *framedata)
|
||
|
|
{
|
||
|
|
ast_free(framedata);
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct ast_frame *hook_event_cb(struct ast_channel *chan, struct ast_frame *frame, enum ast_framehook_event event, void *data)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
int drop_frame = 0;
|
||
|
|
struct frame_drop_data *framedata = data;
|
||
|
|
if (!frame) {
|
||
|
|
return frame;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!((event == AST_FRAMEHOOK_EVENT_WRITE && framedata->list_type == TX) ||
|
||
|
|
(event == AST_FRAMEHOOK_EVENT_READ && framedata->list_type == RX))) {
|
||
|
|
return frame;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (frame->frametype == AST_FRAME_CONTROL) {
|
||
|
|
for (i = 0; i < ARRAY_LEN(controlframetype2str); i++) {
|
||
|
|
if (frame->subclass.integer == controlframetype2str[i].type) {
|
||
|
|
if (framedata->controlvalues[i]) {
|
||
|
|
drop_frame = 1;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for (i = 0; i < ARRAY_LEN(frametype2str); i++) {
|
||
|
|
if (frame->frametype == frametype2str[i].type) {
|
||
|
|
if (framedata->values[i]) {
|
||
|
|
drop_frame = 1;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (drop_frame) {
|
||
|
|
ast_frfree(frame);
|
||
|
|
frame = &ast_null_frame;
|
||
|
|
}
|
||
|
|
return frame;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int frame_drop_helper(struct ast_channel *chan, const char *cmd, char *data, const char *value)
|
||
|
|
{
|
||
|
|
char *buffer;
|
||
|
|
struct frame_drop_data *framedata;
|
||
|
|
struct ast_datastore *datastore = NULL;
|
||
|
|
struct ast_framehook_interface interface = {
|
||
|
|
.version = AST_FRAMEHOOK_INTERFACE_VERSION,
|
||
|
|
.event_cb = hook_event_cb,
|
||
|
|
.destroy_cb = hook_destroy_cb,
|
||
|
|
};
|
||
|
|
int i = 0;
|
||
|
|
|
||
|
|
if (!(framedata = ast_calloc(1, sizeof(*framedata)))) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
interface.data = framedata;
|
||
|
|
|
||
|
|
if (!strcasecmp(data, "RX")) {
|
||
|
|
framedata->list_type = RX;
|
||
|
|
} else {
|
||
|
|
framedata->list_type = TX;
|
||
|
|
}
|
||
|
|
|
||
|
|
buffer = ast_malloc(sizeof(value) + 3); /* leading and trailing comma and null terminator */
|
||
|
|
snprintf(buffer, sizeof(value) + 2, ",%s,", value);
|
||
|
|
for (i = 0; i < ARRAY_LEN(frametype2str); i++) {
|
||
|
|
if (strcasestr(buffer, frametype2str[i].str)) {
|
||
|
|
framedata->values[i] = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (i = 0; i < ARRAY_LEN(controlframetype2str); i++) {
|
||
|
|
if (strcasestr(buffer, controlframetype2str[i].str)) {
|
||
|
|
framedata->controlvalues[i] = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ast_free(buffer);
|
||
|
|
|
||
|
|
ast_channel_lock(chan);
|
||
|
|
i = ast_framehook_attach(chan, &interface);
|
||
|
|
if (i >= 0) {
|
||
|
|
int *id;
|
||
|
|
if ((datastore = ast_channel_datastore_find(chan, &frame_drop_datastore, NULL))) {
|
||
|
|
id = datastore->data;
|
||
|
|
ast_framehook_detach(chan, *id);
|
||
|
|
ast_channel_datastore_remove(chan, datastore);
|
||
|
|
ast_datastore_free(datastore);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!(datastore = ast_datastore_alloc(&frame_drop_datastore, NULL))) {
|
||
|
|
ast_framehook_detach(chan, i);
|
||
|
|
ast_channel_unlock(chan);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!(id = ast_calloc(1, sizeof(int)))) {
|
||
|
|
ast_datastore_free(datastore);
|
||
|
|
ast_framehook_detach(chan, i);
|
||
|
|
ast_channel_unlock(chan);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
*id = i; /* Store off the id. The channel is still locked so it is safe to access this ptr. */
|
||
|
|
datastore->data = id;
|
||
|
|
ast_channel_datastore_add(chan, datastore);
|
||
|
|
}
|
||
|
|
ast_channel_unlock(chan);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct ast_custom_function frame_drop_function = {
|
||
|
|
.name = "FRAME_DROP",
|
||
|
|
.write = frame_drop_helper,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int unload_module(void)
|
||
|
|
{
|
||
|
|
return ast_custom_function_unregister(&frame_drop_function);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int load_module(void)
|
||
|
|
{
|
||
|
|
int res = ast_custom_function_register(&frame_drop_function);
|
||
|
|
return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
|
||
|
|
}
|
||
|
|
|
||
|
|
AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Function to drop frames on a channel.");
|